Tratamento hipofracionado de radioterapia em felinos portadores de carcinoma epidermóide facial / Hypofractionated radiation therapy for the treatment of feline facial squamous cell carcinoma

Avaliou-se a eficácia do protocolo radioterápico hipofracionado no tratamento de felinos portadores de carcinoma epidermóide facial. Um protocolo hipofracionado de radioterapia foi aplicado em cinco gatos portadores de um ou mais carcinomas epidermóides faciais, em um total de 10 lesões neoplásicas, confirmadas por meio de análise histológica. Duas lesões foram classificadas como T1, quatro como T2, duas como T3 e duas como T4. Os animais foram submetidos a quatro frações radioterápicas de 7,6 a 10gy, com intervalo de uma semana entre elas, utilizando-se um acelerador linear com feixe de elétrons. O acompanhamento dos animais foi realizado semanalmente durante o tratamento e aos 30 e 60 dias após o término da radioterapia. Neste estudo, 40 por cento das lesões resultaram em remissão completa, 40 por cento em remissão parcial e 20 por cento não apresentaram resposta ao tratamento. A taxa de resposta encontrada nessa pesquisa foi baixa, porém o protocolo de hipofracionamento radioterápico foi seguro para gatos com carcinoma epidermóide facial e resultou em efeitos colaterais leves/moderados.

The efficacy of hypofractionated radiation protocol for feline facial squamous cell carcinoma was evaluated. Hypofractionated radiation therapy was applied to five cats showing single or multiple facial squamous cell carcinomas, in a total of ten histologically confirmed neoplastic lesions. Of the lesions, two were staged as T1, four as T2, two as T3, and two as T4. The animals were submitted to four radiation fractions from 7.6 to 10 grays each, with one week intervals. The equipment was a linear accelerator with electrons beam. The cats were evaluated weekly during the treatment and 30 and 60 days after the end of the radiation therapy. In this study, 40 percent of the lesions had complete remission, 40 percent partial remission, and 20 percent did not respond to the treatment. Response rates were lower as compared to other protocols previously used. However, hypofractionated radiation protocol was considered safe for feline facial squamous cell carcinoma.

Oral toxicity of the cyanobacterial toxin cylindrospermopsin in mice: long-term exposure to low doses.

The hepatotoxin cylindrospermopsin, a sulfated-guanidinium alkaloid with substituted dioxypyrimidine (uracil) moiety, was isolated from several cyanobacteria species. The acute toxicity of cylindrospermopsin was well established based on intraperitoneal and oral exposure; however, only a few long-term subacute exposure studies were performed to permit a reliable guideline value for cylindrospermopsin in drinking water. In the study reported herein, female and male mice were exposed to cylindrospermopsin in their drinking water. Cylindrospermopsin-containing, Aphanizomenon ovalisporum (cyanobacterium)-free medium was provided as the only source of drinking water, whereas a control group was given a fresh medium for cyanobacteria as drinking water. Over a period of 42 weeks, experiment groups were exposed to cylindrospermopsin concentration, gradually increased from 100 to 550 microg L(-1) (daily exposure ranged between 10 and 55 microg kg(-1) day(-1)). Body and organ weights were recorded, and serum and hematology analyses were performed 20 and 42 weeks after the beginning of the experiment. The most pronounced effect of cylindrospermopsin was elevated hematocrit levels in both male and female mice after 16 weeks of exposure to cylindrospermopsin. The observed changes in the hematocrit level were accompanied by deformation of red blood cells, which were changed into acanthocyte. Based on these results, a daily cylindrospermopsin dose of 20 microg kg(-1) day(-1) (equivalent to 200 microg L(-1)) is proposed as the lowest-observed-adverse-effect level for both male and female mice.

The cyanobacterial toxin cylindrospermopsin inhibits pyrimidine nucleotide synthesis and alters cholesterol distribution in mice.

The hepatotoxin Cylindrospermopsin, a sulfated-guanidinium alkaloid with substituted dioxypyrimidine (uracil) moiety, was isolated from several cyanobacteria species. Our previous studies on the toxicity of cylindrospermopsin and its derivatives suggested that the uracil moiety is crucial for the toxicity and that such toxicity could partly stem from competitive binding of the toxin to a catalytic site(s) involved in the synthesis of pyrimidine nucleotides (i.e., uridine). In the present study we demonstrated that cylindrospermopsin inhibited in a noncompetitive manner the in vitro activity of uridine monophosphate (UMP) synthase complex (responsible for the conversion of orotic acid to UMP) in a cell free liver extract from mice, with an inhibition constant, KI, of 10 microM. Exposure of mice to cylindrospermopsin at subacute concentrations, via drinking water, only slightly affected the in vitro activity of UMP synthase. The typical metabolic disorder associated with the inhibition of UMP synthase activity, known as "orotic aciduria," was not observed under these conditions, but other anomalous metabolic responses related to cholesterol metabolism were developed.

Knowledge, attitudes, and practices of geriatricians regarding patients with dementia who are potentially dangerous automobile drivers: a national survey.

OBJECTIVES: To determine geriatrician knowledge regarding how to prevent a patient with dementia who is a potentially dangerous driver from driving and to determine their willingness to recommend license revocation against the wishes of both the patient and the patient's family. Included is a comparison of responses from geriatricians in California, where related legislation has existed for a decade, with responses from geriatricians from all other US states combined. DESIGN: Survey sample. SETTING: Geriatric practices. PARTICIPANTS: Probability sample of 467 geriatricians. MAIN OUTCOME MEASURES: Survey responses. RESULTS: More than 28% of all geriatricians (95% CI, 24.3%-32.7%) do not know how to report patients with dementia who are potentially dangerous drivers. A 22% difference (95% CI, 13.9%-30.8%) exists between California geriatricians and those in all other US states. More than 75% (95%, CI, 71.5%-79.5%) of all geriatricians agreed that physicians are responsible for reporting patients. More than 86% (95% CI, 83.2%-89.6%) of all geriatricians would contact state authorities despite the objections of the patient, and 72.9% (95% CI, 68.7%-77.1%) would contact authorities despite the objections of the patient's family. CONCLUSIONS: Although most geriatricians will act to protect the public from patients with dementia who are potentially dangerous drivers, many do not know how to report these drivers. Legislation can improve a physician's ability to report patients with dementia who are potentially dangerous drivers.

Attitudes of physicians regarding physician-assisted suicide.

A survey of New Jersey physicians reveals no clear consensus as to whether physician-assisted suicide should be legalized, and most physicians stated that they would not participate in such activities where it is legal to do so. Further studies need to be undertaken.

HCFA's Medicare mortality statistics for a New Jersey hospital.

We assessed the severity of illness in 40 Medicare patients with an acute myocardial infarction to determine whether HCFA's observed-to-predicted mortality ratio was related to quality of care or severity of illness. The authors present a study from a New Jersey hospital.

Advance directives for the elderly: a survey.

In 1991, the New Jersey Legislature passed the New Jersey Advance Directives for Health Care Act. We surveyed the elderly about their knowledge and interest in advance directives, their preferences regarding end-of-life care, and whether their physicians discuss these matters.

Solitary pulmonary nodule in secondary syphilis.

A case of secondary syphilis with a solitary right upper-lobe nodule is presented. Patient presented without any pulmonary complaints or findings. This mass disappeared with residual scar after a full course of penicillin therapy. Our report is the first in the literature that reports a solitary nodule in the upper lobes in secondary syphilis. Previous reports showed nodules only in lower lobes. Our patient also presented with a rectal mass that disappeared on anti-syphilitic therapy.

A new technique for the isolation and purification of the basal lamina from insect tissues.

A new technique for the isolation and purification of basal lamina from insect tissues using cell dissociation at pH 2 is described. Tissue incubation in these solutions results in the spontaneous detachment of cells from the basal lamina which can be collected free of any significant contamination by cellular components. Short lengths of plasma membrane which remain attached to the basal lamina can be removed by subsequent sonication or detergent treatment. Using Malpighian tubules as the primary test tissue, we have found that the procedure only requires a few minutes, works equally well on pooled tissue samples, individual tissue pieces or tissue subregions and involves no loss of basal lamina from the starting material.

Results of epidemiologicalm mineralogical and cytotoxicological studies on the pathogenicity of coal-mine custs.

Risks of developing abnormalities on chest X-rays differ widely between collieries in the Ruhr, despite comparable dust exposures. Simple pneumoconiosis hazard indices have been determined for thirteen collieries, taking into consideration variations in miners' individual cumulative dust exposures, their ages at start of dust exposure, the residence time of dust in their lungs, and the mineral content of the dust. Fine dust samples were taken in five collieries at places selected as representative of seams worked during the past 20 years. They were used for mineralogical and physical analyses and for cell and animal studies. Cytotoxicity of dusts with comparable composition increased with geological age and rank of coal seams. This finding is consistent with results from epidemiological studies.